YouTube algorithm spots world's funniest videos

Emma Woollacott, 13th February 2012

Google researchers have developed an algorithm that ranks the funniest YouTube videos.

The algorithm is based on a large number of criteria - first, just how funny the uploaders appears to think their video is, based on title, description and tags. It also checks for things like audible laughter in the clip itself.

Next, it looks at viewer comments - and in some detail.

"These included sounds associated with laughter such as hahaha, with culture-dependent variants such as hehehe, jajaja, kekeke; web acronyms such as lol, lmao, rofl; funny and synonyms of funny; and emoticons such as :), ;-), xP," says Sanketh Shetty of the YouTube Slam Team.

"We then trained classifiers to identify funny videos and then tell us why they are funny by categorizing them into genres such as 'funny pets', 'spoofs or parodies', 'standup', 'pranks' and 'funny commercials'."

But it gets even more elaborate than that. Apparently, 'LOL' and 'loooool', for example, indicate more amusement than plain old 'lol'.

"We designed features to quantify the degree of emphasis on words associated with amusement in viewer comments," says Shetty. "We then trained a passive-aggressive ranking algorithm using human-annotated pairwise ground truth and a combination of text and audiovisual features."

The researchers have used the algorithm to generate a list of videos that viewers can then vote for on the Comedy Slam page.

So far, more than 65,000 people have voted - and the current leader is a video of a man trying to retrieve a tomato from between the blades of a spinning ceiling fan. He manages it, but at some cost to his ear.